This invention relates to a new and improved evacuator system for transferring liquids in an evaporative recovery system. More particularly, this invention relates to a new and improved evacuator system for transferring for reuse distilled water and reconcentrated chemicals which have been recovered from rinse water effluent.
The present invention is an evacuator system which is efficiently integrated into an evaporative recovery system such as the type of system employed in recycling metal finishing chemicals and rinse water obtained by means of a low temperature vacuum distillation process. In conventional metal finishing systems parts to be plated or finished are submerged in a plating bath and successively rinsed in a sequence of rinse tanks. The resulting rinse water effluent or waste may be recycled to an evaporator unit wherein the effluent is subjected to a partial vacuum under a relatively low temperature below the boiling point of water to provide a distillate of essentially pure distilled water and a concentrate liquid of reconcentrated chemicals. By returning the distillate and the reconcentrated chemicals to the plating system for reuse a number of economies are achieved. The reclaimed chemicals can be reused thus lessening the cost of required chemicals. The recycling of the distilled water represents a savings in the quantity of water required for the metal processing system. In addition, the recycling of the chemicals and the distilled water eliminates costly waste disposal and facilitates compliance with environmental regulations.
Because the chemicals involved in the chemical plating process are often quite corrosive, an effective and efficient waste recovery system must be designed to minimize the corrosive effects of the chemicals as well as the corrosive fumes given off by the chemicals and the waste water effluent. In particular electromechanical pumps are easily damaged and corroded by frequent exposure to plating materials and other chemical wastes. It is therefore an object of the present invention to provide an evacuator system which eliminates the requirement of electromechanical pumps.
The efficiency of a waste recovery system is additionally a function of the degree with which various operational parameters such as the temperature of the evaporator unit, the partial vacuum of the evaporative unit, and the chemical concentration level, can be effectively controlled. A computer controlled system is advantageous for controlling the waste recovery process so that the wastes may be recovered in an efficient and reliable manner and to insure the quality and purity of the recovered products. An additional feature of the evacuator system of the present invention is that the system is efficiently integrated into an automatic computer controlled system for recycling rinse water effluent for reuse in a chemical plating system.